Correlated electron capture in the impact parameter and final projectile charge-state dependence of ECC cusp production in 0.53 MeV u-1F8++Ne

The impact parameter dependence of ECC cusp electron production in collisions of fast, highly charged ions with atoms is investigated by measuring the scattered projectiles in coincidence with cusp electrons emitted at 0 degrees with respect to the beam axis. The absolute probabilities for ECC cusp production show a maximum at b approximately=0.10 au, decrease strongly for smaller impact parameters and more gently toward larger impact parameters. In addition the final charge state of the scattered projectile is also determined simultaneously for each collision event. As a function of the projectile final charge state after the collision these probabilities are large for the case where at least one or more electrons are simultaneously captured into bound states of the projectile, but are surprisingly small for collisions in which a projectile did not capture an electron into a bound state. The observed dependences suggest strongly that correlated electron capture plays an important role in ECC cusp formation.